Transmission Can't See Objects Inside Of The Transparent Object

[mphillips0007]

I am trying to use transmission and I am missing something?  To illustrate the issue I have a basic sphere with transparency turned to 1 and I have small cube inside of the sphere with a solid material.  The whole scene is lit with an HDRI.  When I render you can see the transparent sphere but the cube inside of the sphere is black and reflects the HDRI.  What am I doing wrong?

[lee_griggs]

What is the issue exactly? Do you want the cube to be transparent? What shader is on the cube? Are transmission/specular ray depths high enough? Are you using a skydome or sky?

[mphillips0007]

@lee_griggs thank you for your response.  The cube as a standard_surface attached with no transmission applied. As for transmission/specular ray depths I am assuming you are referencing in my render settings.  I left them at the default of 10 and the problem exist then I turned ray depth to 16 and the problem still exist.  I am lighting the scene with Arnold skydome_light with an HDRI.

[mphillips0007]

@lee_griggs I think I found the solution, but maybe you can explain why and I am not sure if this really is why but it fixed the problem.  When I create a clear material with transparency if I go to the Advanced tab of the material "Caustics" by default is not selected.  If I enable "Caustics" now I can see through the object and see the objects that are on the inside of the transparency. 

[peter_horvath]

The caustics flag should not be relevant here.

Look at the visibility flags (Camera, Diffuse, Specular, etc.) of the skydome light and make sure they are all set to 1. I have a feeling that your Diffuse flag is turned off.

[mphillips0007]

@peter_horvath Thank you for the response.  I have those enabled.  I closed everything down and re-build the scene and now it seems to work.  Maybe some bug or I  disabled something I wasn't seeing?  Again, thank you so much for your response and @lee_griggs .  You 2 seem to always be there to help and have so much knowledge about this software, greatly appreciated.